U.S. patent number 5,866,235 [Application Number 08/804,201] was granted by the patent office on 1999-02-02 for all synthetic fiber interior trim substrate.
This patent grant is currently assigned to Eften, Inc.. Invention is credited to John Fredrick, Harold H. Zaima.
United States Patent |
5,866,235 |
Fredrick , et al. |
February 2, 1999 |
All synthetic fiber interior trim substrate
Abstract
An interior trim substrate and method of making same uses a
corrugated synthetic fiber liner having upper and lower sides. An
upper synthetic fiber liner is bonded to the upper side of the
corrugated liners and a lower synthetic fiber liner is bonded to
the lower side of the corrugated synthetic fiber liner. In this
way, an all synthetic fiber headliner substrate which is or can be
made 100% recyclable, is formed.
Inventors: |
Fredrick; John (Davisburg,
MI), Zaima; Harold H. (Auburn Hills, MI) |
Assignee: |
Eften, Inc. (Auburn Hills,
MI)
|
Family
ID: |
25188409 |
Appl.
No.: |
08/804,201 |
Filed: |
February 21, 1997 |
Current U.S.
Class: |
428/182; 156/242;
156/245; 264/257 |
Current CPC
Class: |
B32B
3/28 (20130101); B60R 13/0225 (20130101); B32B
5/26 (20130101); B32B 37/04 (20130101); B29D
24/001 (20130101); Y10T 428/24694 (20150115); B32B
2307/102 (20130101); B32B 2605/003 (20130101); B32B
2037/148 (20130101) |
Current International
Class: |
B60R
13/02 (20060101); B32B 3/28 (20060101); B29D
24/00 (20060101); B32B 003/28 (); B29C
047/00 () |
Field of
Search: |
;428/150,182,174,178,198
;264/103,119,177.1,257,321,241 ;296/210,214,901,146.7
;156/62.2,244.25,242,245 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Loney; Donald
Attorney, Agent or Firm: Notaro & Michalos P.C.
Claims
What is claimed is:
1. An interior trim substrate comprising:
a corrugated synthetic fiber layer having upper and lower
corrugated sides with corrugated flutes with peaks and valleys and
made of a sheet of polyester or polypropylene;
an upper synthetic fiber liner bonded to peaks of the flutes on the
upper side of the corrugated synthetic fiber layer; and
a lower synthetic fiber liner bonded to peaks of the flutes on the
lower side of the corrugated synthetic fiber layer, the liners both
being sheets of polyester or polypropylene and hollow spaces being
left between the upper and lower corrugated sides of the layer and
the liners.
2. A substrate according to claim 1 wherein the upper and lower
liners comprise thin sheets of synthetic fiber liner connected to
peaks of the flutes on both sides of the corrugated liner.
3. A method of making an all synthetic fiber interior trim
substrate comprising:
forming a corrugated synthetic fiber layer having upper and lower
corrugated sides with corrugations, the layer being made of
polyester or polypropylene;
laying an upper synthetic fiber liner onto the upper side of the
corrugated layer to connect with correguation peaks of the upper
side of the layer to leave hollow spaces between the layer and the
upper liner;
laying a lower synthetic fiber liner onto the lower side of the
corrugated layer to connect with corrugation peaks of the lower
side of the layer to leave hollow spaces between the layer and the
lower liner; and
thermoforming the liners to attach the upper and lower lines to the
corrugated layer, the lines both being made of polyester or
polypropylene.
4. A method according to claim 3 wherein the upper and lower liners
comprise thin sheets of synthetic fiber liner connected by the
thermoforming to peaks of the corrugations on opposite sides of the
corrugated layer.
Description
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates, in general, to substrates used for
interior trim and especially to headliner substrates for motor
vehicles, and in particular, to a new and useful headliner
substrate and process for making the same, where the entire article
of manufacture is made of synthetic fibers such as, but not limited
to polyester (PET), polypropylene (PP), and nylon that enables it
to be 100% recyclable or can be made 100% recyclable.
U.S. Pat. No. 5,022,943 and 5,134,014, and U.S. patent application
Ser. No. 08/755,283 filed Nov. 22, 1996, which are all incorporated
here by reference, disclose methods, structures and materials for
composite substrates of the type to which the present application
relates.
Substrates for interior trim are known to be manufactured from
various natural and synthetic fibers. In particular, headliners are
known which are made from corrugated fiberboard and thermoplastic
composites. The composite may include an upper kraft paper layer
and intermediate thermoplastic film layer (e.g. polyester or
polyethylene), an inner kraft liner, an inner thermoplastic layer,
and a corrugated fiberboard medium.
It is also known to use fiberglass in a headliner for its strength,
dimensional stability and acoustic absorption characteristics.
Further, it is also known to use polyurethane foam sandwiched
between two glass mats for its strength and dimensional stability
of the glass mats and for acoustical enhancement of the foam. It is
also known to use polyester mat sandwiched between glass mats again
for its strength and dimensional stability as well as for its
acoustical enhancement. Finally, attempts have been made to use
only polyester mats, however, dimensional stability and structural
rigidity could not be maintained without incurring exorbitant costs
or without using glass mats to increase the rigidity and
dimensional stability of the overall product. In today's market,
there is no one product that can currently meet the stringent
demands of the automotive industry, which are a low cost,
lightweight interior trim substrate with superior acoustical
performance and moldability while passing the dimensional stability
and transverse strength requirements while also being 100%
recyclable.
The main reason to develop an all synthetic fiber headliner is
because it can meet all the aforementioned requirements while still
providing the ability for the entire headliner to be 100%
recyclable. Current attempts to develop an all synthetic fiber
interior trim substrate has been supplied using a thick mat of high
melt polyester fibers mixed with low melt PET fibers called binder
fibers. This mat is then thermoformed in a hot molding die, then
transferred to a marriage tool where a polyester non-woven cosmetic
cover material is bounded to the polyester fiber substrate. Please
see U.S. patent application Ser. No. 08/755,283 for details
concerning these dies and tools.
In some processes, the mat is preheated with hot air blowing or
radiating heat through the substrate. During the heating process,
the low melt PET binder fibers soften whereby binding together the
high melt PET fibers. The temperature is not high enough to soften
the high melt fibers. The composite is then placed into a molding
die in conjunction with the polyester cosmetic covering material
and formed and bonded simultaneously. This system yields a 100%
polyester headliner which is 100% recyclable. Also, due to the
fibrous nature and high loft of the substrate, it performs very
well as sound absorber and has excellent molding.
Currently in the automotive industry, fibrous material such as
fiberglass is considered the benchmark for sound absorption.
However, due to the potential undesirable characteristics of the
glass fibers during the processing of the substrate as well as in
the final product, the automotive industry is attempting to
eliminate fiberglass type products as an interior trim substrate.
Resinated cotton or shoddy and phenolic impregnated polyester
fibers both have proven to be effective sound absorption
substrates; however, both products use phenolic resin as a
strengthening and binder agent which are considered to be
undesirable due to the formaldehyde and odor this product produces
as well as its non-recyclable characteristic. Synthetic fibers are
seen as a major alternative to eliminate the undesirable effect of
fiberglass and phenolic impregnated fibers.
Cost is the major prohibitive issue in today's all polyester
interior trim substrate. Polyester fibers are very expensive
compared to other substrates available on the market. Furthermore,
in order to attain a substrate thickness of 15-20 mm (as required
for superior sound absorption), a very thick mat must be used prior
to compression, otherwise, there will not be enough pressure to
bond enough binder fibers together, resulting in a headliner that
will not have the integrity to pass the automotive specifications
for transverse strength as well as through the environmental
chambers. As a result, in order to enable the current product to
pass the specification, the percentage of binder fibers which as
double the cost of the matrix fibers must be increased and
simultaneously the amount of mass must be increased. Although this
product became a salable product that is 100% recyclable, the
product is neither cost effective nor light weight. This leads to
the primary reason for the present invention.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a headliner
substrate which is made entirely or predominantly of synthetic
fibers such as polyester or polypropylene, so that the substrate
can be recycled or be made recyclable. The headliner of the
invention is also cost effective, lightweight and has similar
advantageous characteristics of strength and acoustic absorption to
its fibrous counterparts and better sound absorption
characteristics as other substrates that are not made from fibrous
material.
A further object of the present invention is to provide a method
for manufacturing the all synthetic fiber substrate into various
interior trim components such as a headliner.
Another object is to provide a 100% synthetic fiber interior trim
headliner substrate that does not require a thick mat of fibers
with a high percentage of the more costly binder fibers in order to
pass the testing requirements of the automotive industry and to
maintain low weight. If a thick mat is necessary for additionally
enhanced acoustical performance, less fibers would be required
compared to other synthetic fiber substrate constructions on the
market. This construction will greatly reduce both cost and weight
from the product.
The various features of novelty which characterize the invention
are pointed out with particularity in the claims annexed to and
forming a part of this disclosure. For a better understanding of
the invention, its operating advantages and specific objects
attained by its uses, reference is made to the accompanying
drawings and descriptive matter in which a preferred embodiment of
the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a partial, schematic, perspective view of the starting
components of a headliner substrate of the present invention;
FIG. 2 is a view similar to FIG. 1, after the completed product
such as a headliner, rear parcel tray or door panel has been
formed;
FIG. 3 is a sectional view of another embodiment of the invention
during an initial arrangement of components;
FIG. 4 is a view similar to FIG. 3 of the completed product after
it has been formed; and
FIG. 5 is a view similar to FIG. 4, illustrating a still further
embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, the invention embodied in
FIG. 1 comprises the components that form the all synthetic fiber
interior trim product substrate of the present invention.
An important feature of the invention is to corrugate a synthetic
fiber liner through existing and known corrugators. Prior to
molding, the substrate includes a flat synthetic fiber liner 12
bonded to a corrugated synthetic fiber liner 14. The liner 12
represents the sheet metal side of the headliner. On the car
interior side of the substrate, is a synthetic fiber mat 16
comprised of a mixture of high melt synthetic fibers and low melt
synthetic binder fibers.
After thermoforming, as shown in FIG. 2, the low melt fibers of the
synthetic fiber mat 16 will soften and adhere to the corrugated
synthetic fiber liner 14 as well as bonding the high melt fibers
within the mat. The corrugated synthetic fiber liner 14 in this
construction allows for the use of much less synthetic fibers due
to the flexural strength created by the fluting due to its I beam
effect. The synthetic fiber mat 16 can be of much lower fiber
density than current technology without the corrugated I beams.
This system allows the use of a thick substrate for excellent sound
absorption, only on the interior side, limiting the fibers
required. A cosmetic cover sheet 17, also of synthetic fiber,
completes the composite. Cover sheet 17 can be adhered to mat 16 in
one of the die or marriage steps.
As shown in FIGS. 3 and 4, where like numbers are used for similar
elements, a synthetic fiber mat 18 can be used on both sides of the
corrugated synthetic fiber liner 14. Again this allows for the use
of a thick substrate for good sound absorption while reducing the
total amount of fibers required.
When excellent sound absorption is not a requirement, a
construction without the thick synthetic fiber mat can be used.
FIG. 5 illustrates construction where synthetic fiber lines 12 and
13 can be placed on both sides of the corrugated synthetic fiber
layer 14. This would be a lower cost alternative for entry level
vehicles.
In many cases, synthetic fiber liners specially constructed to
achieve sound attenuation by causing a pressure drop in the
amplitude of sound as opposed to sound absorption through diffusion
of sound can be used to greatly reduce sound without the use of
highly lofted mats greatly reducing weight and cost. The
construction will be similar to FIG. 5 with the use of specially
formulated fiber construction. These products are commercially
available and covered by U.S. Pat. No. 4,420,526.
All of these embodiments can be made 100% recyclable by using a
synthetic fiber liner either spunbond or non-woven and
corresponding synthetic fiber cosmetic cover material, shown for
example at 17 in FIG. 2.
The unique aspect of these constructions is with the corrugated
synthetic fiber liner. Synthetic fiber weights and densities may be
varied to meet the needs of every vehicle line from entry level to
high end luxury vehicles. The corrugated synthetic fiber gives the
construction good flexural strength while maintaining low cost and
a lightweight construction by allowing the use of less synthetic
fibers in the substrate. Further, excellent acoustical results can
be achieved by either lofting the product to the thickness of 15-20
mm or through the use of the specially formulated synthetic fiber
liners that will promote pressure drop to attenuate unwanted noise
in the vehicle interior. The substrates are also fully moldable
since the synthetic fibers are a thermoplastic.
By low melt synthetic binder fiber, melting at from about
100.degree. C. to 150.degree. C. is meant. High melt fibers melt at
about 150.degree. C. to 250.degree. C. The proportion of high melt
to low melt fibers which is contemplated for the mats 16 and 18,
are about 5.0% to 45% low melt binder fibers and the remainder high
melt matrix fibers. The headliner substrate is preferably in the
final range of 2 mm to 20 mm with acoustic headliners being
advantageously from 15-20 mm.
The prior art mats before molding are generally from 20.0 mm to
40.0 mm thick while the starting mats of the present invention can
be from 4.0 to 25.0 mm thick and have reduced density. The prior
art density is about 200 to 350 oz. per square feet while the mats
of the present invention can have a density from about 2.5 to 250
oz. per square foot and a starting thickness from about 5.0 to 25.0
mm.
When compressed in a heated mold so that the composites of FIGS. 1
and 3 are formed into the final substrate of FIGS. 2 and 4
respectively, temperatures of about 140.degree. C. to 200.degree.
C. are utilized and pressures of 30 to 80 tons and duration of 15
to 45 seconds. For the through air heat system the hot air heat
temperature would be from 175.degree. C. to 250.degree. C. and the
molding temperature shall be 30.degree. C. to 80.degree. C.
Liners 12, 13 and corrugated liner 14 are advantageously made of
synthetic fiber sheet material having a thickness of about 0.3 to
2.5 mm.
While specific embodiments of the invention have been shown and
described in detail to illustrate the application of the principles
of the invention, it will be understood that the invention may be
embodied otherwise without departing from such principles.
* * * * *